The beaklike teeth of a parrotfish are used primarily to bite off pieces of stony coral. These fused teeth form a strong, parrot-like beak that scrapes or bites chunks of coral rock to access the algae growing on the coral surface or to reach the soft coral polyps beneath the skeleton

. The parrotfish does not eat the hard coral skeleton itself for nourishment but rather the coral polyps and algae living on or inside the coral

. The parrotfish's beak is composed of roughly 1,000 teeth arranged in rows and cemented together, allowing it to bite into coral effectively. When the beaklike teeth wear down, new teeth continuously replace them from behind

. After biting off coral pieces, parrotfish use a second set of specialized grinding teeth in their throat (pharyngeal mill) to pulverize the coral into fine sand, which is then excreted

. In summary, the beaklike teeth of a parrotfish are used to:

• Bite off pieces of hard coral to access algae and coral polyps.
• Scrape live coral heads or coral rock surfaces.
• Enable the parrotfish to feed on coral reef material that is then ground and digested to extract nutrients

This feeding behavior also contributes significantly to coral reef ecology by producing sand and opening spaces for other reef organisms to settle